Bibliometric indicators of the Croatian Medical Journal – can small non-profit journal compete in the bibliometrics arena?

Since its establishment, editors of the Croatian Medical Journal (CMJ) have invested enormous effort to attract internationally recognized authors, increase the quality of domestic submissions, and improve the review process by recruiting well-educated local reviewers, continuously educating both potential authors and reviewers. In addition, an important step in achieving international visibility was the inclusion in the international bibliographic databases. The CMJ has been covered by the Scopus database since 1992, with 2580 articles indexed until 2021 (1992 and 1993 were represented selectively, with only 9 and 10 articles, respectively). Since 1998, the CMJ has been indexed in Med-

. Distribution of the Croatian Medical Journal articles indexed in the Science Citation index expanded according to their geographical origin. Data were retrieved by searching the Web of Science Core Collection (on 11/10/2022) for the publication title "Croatian Medical Journal. " "Countries/regions" represented with 20 or more items (24 countries) are specified, while countries with fewer than 20 items (total 368 articles from 71 countries) are represented as "others, " among 2731 items. line/PubMed, and since 1999 in Current Contents/Clinical Medicine and Science Citation Index Expanded, with more than 2300 articles available in these databases. Publishing in open access also increases international visibility of a journal, so the CMJ uses the Diamond Open Access model, with no author processing fees or fees to access the published articles. Besides the CMJ's web site, the journal has since 2006 been freely available on PubMed Central (fullparticipation base) and on the Hrčak portal, a local platform for Croatian scientific and technical journals.
One of the goals of the CMJ has been to represent a gateway for Croatian medical researchers to the global community. The articles from Croatian authors account for approximately 40% of all the journal's entries in Science Citation Index Expanded and 47% in Scopus. In addition, the CMJ has also attracted articles from neighboring and regional countries, which together with the articles by Croatian authors, account for more than a half (56%) of the journal contributions ( Figure 1).
The annual number of articles published in the CMJ has varied over time, reflecting changes in editorial policies ( Figure  2A). It peaked between 2001 (when the journal switched from four to six issues per year) and 2008. After that, the number has remained under 100. As journals' influence is often assessed through the number of citations and impact factor (IF), many journal editors considered adjusting their policies to improve these metrics. Some examples of these adjustments are increasing the proportion of review articles, which are expected to be more cited, or increasing the proportion of non-citable items, such as letters and editorials, which receive citations but are not included among citable items during IF calculation (3). The CMJ's editorial poli- cy has been mainly targeted at the improvement of writing skills of local authors, and encouraging authors to submit high-quality reports. In line with the journal's scope (4), the majority of published items are original articles ( Figure 2B). Despite many known limitations and fierce criticism (6), the IF of a journal and its quartile (Q) rank in a respective subject category remain the most important criteria when it comes to assessing the journal quality. Since the CMJ's founding, the journal's IF has increased substantially, peaking in 2021 ( Figure 3A). However, the journal remains in the third quartile (119 out of 172 journals) in its category -Medicine, General & Internal. The best rank was achieved between 2009 and 2011, and the journal remained in the second quartile until 2016 ( Figure 3B). In the field of biomedicine, Medicine, General & Internal is one of the most competitive categories where the highest ranking journal has an IF of 202.7, and more than 20 journals have IFs greater than 10. However, even in Q3, the CMJ's ranks higher than many well-established medical journals with a long publishing history. Therefore, assessing journal quality based on its rank relies on an arguable assumption that a few citations make a big difference (7). In addition, the total number of journals in this category increased from 112 in 2001 to 172 in 2021, so the decrease in the CMJ's rank may be attributed to a rapid increase in IF of more recently included open-access journals over the last decade.
Since its establishment, the CMJ has earned 25 891 citations (92.6% journal-independent citations). The majority of these citations were received by items classified as articles (81.6%) and editorial material (11.9%), in line with their frequencies in the total number of articles ( Figure 4A). However, when the average number of citations per year is normalized according to the article type, reviews attracted more citations, followed by original articles, while each editorial material item received on average one citation in four years ( Figure 4B). The average normalized number of citations per year for all articles is 0.45, so each article published in the CMJ was cited approximately once in two years. However, articles published between 2007 and 2017 were cited approximately once a year, pointing to an overall increase in the citation rate ( Figure 4C).
The CMJ articles are characterized by a long cited half-life, an indicator representing the median age of articles cited in a particular year (8). According to Journal Citation Reports (JCR), the cited half-life of the CMJ in the recent decade fluctuated between 6.1 and 10. In the current, 2021, edition of JCR the CMJ is among the 30 journals with the longest half-life in the category Medicine, General & Internal. On the other hand, the immediacy index, an indicator representing the number of citations that articles attracted in the publication year, was low (between 0.1 and 0.6). According to the immediacy index, the CMJ in the 2021 edition of JCR ranked the same as according to the impact factor (119 out of 172 journals in category Medicine, General & Internal). Clearly, the articles published in the CMJ need more time to receive citations, but also remain cited for a long time, so the normalized citation number of recent issues is expected to increase. This is also evident when ranking the articles according to their total, vs average, citation numbers. Some of the more recent articles with highest average normalized citation number per year, although at the moment have fewer total citations, in future might become most cited according to both criteria (Table 1).
Besides the number of citations and IF, a journal's influence in overall scientific community is reflected in Eigenfactor score and Article Influence Score (8). These are weighted indicators that, together with the number of citations, take into account also the source of citations. Therefore, the weight assigned to citations from high-impact journals is greater than the weight of citations from the low-impact journals. According to Eigenfactor score, the CMJ ranked 137th, and according to article influence score, 120th out of 172 journals in the category Medicine, General & Internal. This is not surprising since the CMJ is predominantly cited in journals from the subject categories with lower citation rates and IFs, such as forensics, or in mid-ranked general medical or research journals ( Figure 5).
Since the establishment of the CMJ, editors have monitored the citation rates and IF (5,10). In the first fifteen years, marked by development and expansion of the journal, citation rates, IF, and journal rank in its subject category were continuously increasing. Over the recent fifteen years, indicators have varied depending on fluctuations in editorial policies, but also depending on external factors. Recent decades have seen an explosion of open-access journals, some quickly achieving positions in Q1 and high IFs. Additional imbalance was created by a recent surge in COVID-related research (11). Thus, there is a trend of overall decrease in rank even for reputable scientific journals with high quality requirements and rigorous peer review; this affects small, peripheral journals even more. Non-profit journals often do not possess the required infrastructure and personnel to compete with the production rates and outreach strategies of professional publishers charging for article processing.   and authors prefer publishing in journal "brands, " so in this game small journals do not stand a chance. However, increased awareness about shortcomings of purely bibliometric assessment, and recent requirements for reforming the evaluation of research output (12) will hopefully improve the position of the CMJ and other journals that insist on best editorial practices and rely on "passion for publishing and publishing with passion" (13).